Abstract

Principal aspects of the problem of sound scattering from an object of complex form (CSO) in a free field and in an irregular waveguide are investigated. The CSOs are prototypes of real artificial submarine objects [I. L. Oboznenko, ComplexShapedObjectDetectionandClassification (EG&G WASC, Washington, 1995)]. The CSO is represented by a sum of the interacting elements of local reflection (LREs). It is shown that the LREs CSO are partly coherent scattered. In this condition, the CSO is a multipatch object containing glistening points (part of the first Fresnel zone of each LREs). Temporal structure computations of the multipatch echosignals from the four CSO’s models of real constructions have been made within ray approximation in imitation of an irregular waveguide. It is shown that the real signal can vitally distort and exceed the length of the CSO’s echosignal, an irregular waveguide caused by the multipath propagation and the multipatch CSO. This difference is observed by a statistical shift of the CSO along the waveguide direction at a different depth. Some classification indications of the CSO were provoked by scattering in an irregular waveguide.